Soak skewers in water. Preheat broiler. Put 6 shishito peppers on each skewer and place on baking sheet. Drizzle oil over peppers and rub to coat with fingers. Place baking sheet with peppers under broiler for 1-2 minutes until blistering and slightly charred. Remover from oven. Meanwhile combine preserves with vinegar in a small bowl and brush over both sides of peppers. Season with salt.